The correct answer is A. Zero.
The slenderness ratio of a column is defined as the ratio of its effective length to its least radius of gyration. The effective length is the length of the column that is effective in resisting bending, and the least radius of gyration is the smallest radius of the cross-section of the column that is effective in resisting bending.
A column that is supported throughout its length by a masonry wall has an effective length of zero, because the masonry wall provides lateral support to the column and prevents it from buckling. Therefore, the slenderness ratio of a column supported throughout its length by a masonry wall is zero.
Option B is incorrect because the slenderness ratio of a column is not typically equal to 10.
Option C is incorrect because the slenderness ratio of a column is not typically equal to 100.
Option D is incorrect because the slenderness ratio of a column cannot be infinity.